Join Andy Needham for an in-depth discussion in this video Using Speed to control particle speed, part of X-Particles 3 for Cinema 4D Essential Training.
- If you want to control the speed of your particles the aptly named Speed Modifier is what you'll want to use. Let's look at some examples. In this setup, the emitter doesn't have any speed at all. So the particles are just going to stay where they were born. Let's add a speed modifier from the Motion Modifiers menu. The default mode is set to incremental which means it's going to incrementally change the value over each frame.
And we can add some variation to this. If I make this long you can see a bit better. And you'll notice with this speed modifier we can actually go beyond the particle speed change. So we get some interesting effects where some particles appear to be stood still. If we move on and look at some of the different modes... So, in this example the emitter has a constant speed of 100.
And using the acceleration operation the current speed is multiplied by the exponential value. So you can see, if we zoom out, they're going to get quicker and quicker because that value, the speed that we had initially set is just going to get multiplied and multiplied as we go through time. This can also be a negative number. So if our particles were going very fast to begin with...
Let's just rewind so we've got a clean playback. They're going to be slowed down exponentially until all their speed is gone. In this example the emitter has a speed of 150 with some variation. And if I enable this speed modifier the operation is set to absolute. That's going to say, right, this is now the particle speed.
And we're also using a falloff as well. So once it gets into the zone those particles go up, put the brakes on and their speed changes to be 50 with a bit of variation. From that point on, that's it, that's all they know. So we could use another modifier straight afterwards to speed them up again. So they're going really, really slow and then as soon as they get into the falloff area of the speedup modifier they get really, really fast.
So you can use this to vary the speed of your particles. There is just one more mode that we're going to look at. The final operation mode that we can look at is the Use Spline mode. The value that we have here, if we double-click on it we can see it's 150. And that's interesting because our initial particles had no speed at all. You see they're... just generating there with no speed This is over the particle lifetime remember so from when they were born, they're going to get a speed of 150.
What we can do is just say, "As you get older. " We're going to slow down." So we're going to press Shift-F, rewind. And there we go. We can use a spline to control the speed over the lifetime of the particles. We can now speed-up and slow-down our particles in a variety of ways using the speed modifier.
- Working with the Emitter tabs
- Adjusting particles with modifiers
- Creating visible particles
- Using sprites
- Colliding, freezing, and lighting particles
- Caching in X-Particles
- Applying constraints
- Adjusting materials settings
- Sculpting particles
- Saving and loading presets